(a) Technical Field
The present invention relates to a novel biosurfactant produced by Aureobasidium pullulans. 
(b) Background Art
The present invention relates to a biosurfactant produced by Aureobasidium pullulans) sp. L-3-GPY that is a biosurfactant-producing strain.
A surfactant is a substance having both a hydrophilic moiety and a hydrophobic moiety in a single molecule. This characteristic can change the nature of the surface of a material and/or the interface between materials, thereby reducing a material's surface tension. In an aqueous phase, a surfactant reduces the attractive forces between water molecules. As the concentration of the surfactant increases, a micelle structure can form. A micelle structure is an aggregate of surfactant molecules consisting of external hydrophilic moieties and internal hydrophobic moieties. When a surfactant is placed in a hydrophobic solution, such as a hydrocarbon solution, the surfactant can form an emulsion. Surfactants have dispersibilty, permeability, wettability, emulsifying properties, bubble-forming properties, and the like. Surfactants allow for biodegradation of microorganisms by increasing detachment and solubility of petroleum hydrocarbons (Deshpande et al, 1999. Water Res., 33, 351-360; Doong and Lei, 2003. J. Hazard Mater., 96, 15-27).
While surfactants have been synthesized in small quantities from oil and fat in the past, surfactants are currently chemically synthesized on an industrial mass production scale from coal, oil, and the like. Surfactants are widely used in various industries such as electrical, electronics, construction, machinery, printing, paper manufacturing, and textile industries. However, chemically synthesized surfactants are manufactured via a complicated process, are threatening to aquatic ecosystems due to their formation of bubbles on water surfaces thereby blocking the penetration of sunlight and oxygen, and become a cause of water pollution due to eutrophication induced from phosphates that are formed from phosphorus added to the surfactants to improve detergency. In addition, chemically synthesized surfactants are not easily degradable, due to very low biodegradability, and they readily accumulate in the ecosystem, thereby causing serious environmental problems. In contrast, biosurfactants, surfactants that are intracellularly or extracellularly produced by microorganism strains such as yeast, fungi, and bacteria (Lee et al, 2002. Kor. J. life science, 12, 745-751) are biodegradable and are eco-friendly materials with lower toxicity than synthetic surfactants. Furthermore, biosurfactants can be used for highly specific purposes due to their complex chemical structures and they are not easily synthesized by conventional methods. Additionally, biosurfactants are very useful since they have similar physical and chemical effects to chemically synthesized surfactants, such as surface tension reduction and temperature and pH stability enhancement (Ishigami et al., 1987. Chem. Lett., 763).
Biosurfactants have been widely used in various industrial fields where chemically synthesized surfactants are used such as medicines, foods, cosmetics, detergents, secondary recovery of crude oil, pulp and paper industry, onshore and offshore oil decontamination, degradation of oil and fat in treatment tanks, and the like.
In general, Aureobasidium pullulans strains are known to produce a polysaccharide called beta-glucan. Beta-glucan has an immune stimulant effect and is found in the cell walls of yeast, mushrooms, grains, and the like. Beta-glucan activates the immunity of normal human cells. This suppresses the proliferation of cancer cells and the recurrence of cancer, reduces blood sugar level and blood cholesterol level, and improves lipid metabolism thereby suppressing the formation and accumulation of body fat.
However, it has not yet been reported that Aureobasidium pullulans strains produce biosurfactants.
The above information disclosed in this Background section is provided solely for enhancing the understanding of the background of the invention and, therefore, it may contain information that is not prior art already known in this country to a person of ordinary skill in the art.